1. Field of the Invention
The present invention relates to a display device, and particularly relates to a display device having a light-emitting element. In addition, the invention relates to an electronic apparatus including the display device having a light-emitting element.
2. Description of the Related Art
In recent years, a mobile phone is widespread with the advance of communication technology. It is expected that a moving image will be transferred further and more amount of information will be transmitted in the future. On the other hand, a personal computer (PC) for mobile use has been produced due to the weight reduction. An information terminal called a PDA originated in an electronic notebook is produced a lot and being widespread. In addition, with development of display devices, the majority of such portable information devices is provided with a flat panel display.
Moreover, in recent years, in an active matrix display device, productization of a display device using a low-temperature polysilicon thin film transistor (hereinafter a thin film transistor is referred to as a TFT) has been promoted. Since a signal driver circuit can be formed integrally in the periphery of a pixel portion as well as a pixel by using low-temperature polysilicon, downsizing and high definition of a display device are possible, and such a display device is expected to be more widely used in the future.
As for such a display device for mobile devices, a case of displaying such as an electronic book may be considered. In such a case, it has been considered that a screen is kept still, and a controller and a driver for driving the display device are stopped at this time so that reduction of power consumption is achieved. There is a means thereof in which a static memory (typically, an SRAM; however, it is not limited to SRAM) is arranged in a pixel region, and information of a still image is stored in the static memory to keep displaying the still image. The example is described in the following Patent Document 1.
In addition, the portable information device includes in its category a small liquid crystal television, a digital still camera, a video camera, and the like. A display in a delta arrangement is used for a display of the portable information device for displaying such a natural image, in many cases. The delta arrangement is a method to arrange pixels while shifting for each row as shown in FIG. 2. The delta arrangement has been used in many times in displaying a natural image, from the past.